chore(examples): fix jest test dependencies

[aldarund]

No description provided.

[codecov-io]

Codecov Report

Merging #5155 into dev will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##              dev    #5155   +/-   ##
=======================================
  Coverage   96.06%   96.06%           
=======================================
  Files          73       73           
  Lines        2463     2463           
  Branches      625      625           
=======================================
  Hits         2366     2366           
  Misses         81       81           
  Partials       16       16

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 52fe145...fc37ef6. Read the comment docs.

[clarkdo]

Is babel-core for babel-jest? babel-jest 24 has already upgraded to @babel/core

[aldarund]

@clarkdo its for vue-jest as i see
https://codesandbox.io/s/github/nuxt/nuxt.js/tree/dev/examples/jest-vtu-example broken without babel-core.

AIL components/Btn/Btn.spec.js
● Test suite failed to run

Cannot find module 'babel-core'

However, Jest was able to find:
    './Btn.spec.js'
    './Btn.vue'

You might want to include a file extension in your import, or update your 'moduleFileExtensions', which is currently ['js', 'json', 'vue'].

See https://jestjs.io/docs/en/configuration#modulefileextensions-array-string

  at Object.<anonymous> (node_modules/vue-jest/lib/compilers/babel-compiler.js:1:15)

[clarkdo]

How about using vue-jest 4.0-beta?

[aldarund]

if its stable enough it would be good idea :)

[aldarund]

@clarkdo tested, work fine. updated to 4-beta2

[clarkdo]

LGTM